This invention relates to a magnetic head assembly of a swing arm type for use in carrying out recording or reading operation, namely, access operation to a magnetic recording medium, such as a magnetic disk.
Such a magnetic head assembly includes a plurality of arms having a first end carrying a magnetic head and a second end which is pivotally coupled to a mounting member. The arms are swingable around an axis of the mounting member. Accordingly, the magnetic head assembly is called the swing arm type.
When the access operation is required, the arms are pivotally swung by an actuating device to move the magnetic heads along the recording mediums. In the manner known in the art, the recording medium has a plurality of tracks for keeping records of signals for reproduction. The magnetic head has a head position on a selected one of the tracks. The head position is controlled by a position signal which is representative of the head position. The position signal is derived from a suitable detecting device, such as a particular magnetic head which also scans the recording medium. The first-mentioned magnetic head will herein be referred to simply as a magnetic head.
In order to reliably carry out the access operation, it is necessary to exactly control a positional relation between the magnetic head and each of the tracks of the recording medium. However, it is difficult in a conventional magnetic head assembly of the swing arm type to control the positional relation. The difficulty comes from the fact that the mounting member and the recording medium are deformed as a result of a temperature change. This makes the magnetic head have a position error which is called a thermal off-track in the art and is caused by a temperature difference between the time of recording and the time of reading. Due to the position error, it is unavoidable that the tracks can not be densely recorded on the recording medium.